Concrete surfacing machine



1946- G. E. TROXELL CONCRETE SURFACING' MACHINE 3 Sheets-Sheet l Filed March 4, 1943 7 May 14, 1946. G. E. TROXELL 2 GONCRETE SURFACING MACHINE I .Filedmarcb. 4, 1.943 5 Sheets-Sheet 2 U n r. K \N M k. ..m

ay 1946- G. E. 'DI'ROXELL 2,400,321

CONCRETE SURFACING MACHINE Filed March 4, 1943 s Sheets-Sheet 3 Patented May 14, 1946 P UNITED STATE CONCRETE SURFACING MACHINE George Earl Troxell, Berkeley,

Kalman Floor Company, Inc., a corporation of Delaware Galif., assignor to New York, N. Y.,

Application March 4, 1943,se ria1 No. 477,981 2 Claims. (01. 94-45) The present invention relates to concrete surfacing machines and particularly to machines for smoothing the surfaces of freshly deposited concrete slabs after such surfaces have been levelled or screeded by other means. 7

It has been proposed that the level surface of a freshly deposited concrete slab may with great advantage be subjected to the smoothing action of a surfacingmachine or float comprising two elongated parallel members, the lower work-engaging surfaces of which are disposed approximately in a common plane, and which members are reciprocated longitudinally relatively to each other as they are simultaneously advanced in a direction normal to their parallel axes. A concrete surfacing machine of this type, which has been found to function in a superior manner is disclosed, for instance, in the pending application of Gregory F. Crock, Patent No. 2,386,662 granted October 9, 1945. The machine which comprises the subject matter of the application referred to includes a motor for effecting relative longitudinal movements of the two work-engaging members, the motor being mounted upon one such member and its power output shaft operatively connected to the second, member. While the machine described and illustrated in the applicationmentioned has proven in actual use to be well suited for the surfacing of concrete, I have discovered that, by the addition to that machine of means for effecting the vibration at high frequency of its work-engaging surfaces, by the redesign of the motor supporting means, and by providing novel driving connections from the output shaft of the motor to the vibrating means and to the mechanism for effecting relative longitudinal reciprocation of the two work-engaging members, the operation of the machine as a whole can be substantially improved and a superior result obtained insofar as the product of the machine is concerned, i. e., the resulting concrete slab has a denser, smoother surface, superior in appearance and more wearresisting and durable.

One form of machine for accomplishing the desired objects is illustrated, by way of example, in the accompanying drawings in which:

Figure 1 is a side elevation of the machine, as seen from the operators side;

Figure 2 is a top plan view of the machine; Figure 3 is a section on line 3-3 of Figure 2; Figure 4 is a section on line 4-4 of Figure 2; Figure 5 is a similar section, from which certain of the operating parts have been omitted, a somewhat modified form of machine resulting; Figure 6 is a section on line B--6 of Figure 2, upon a somewhat larger scale, certain portions of the machine which would be shown in a full section being omitted;

Figure 7 is a section on line 1-1 of Figure 6; and

Figure 8 is a view generally similar to Figure 1, portion of the machine having been broken away, how-ever, and certain'clutch operating elements being shown in positions different from those in which they are shown in Figure 1.

The two elongated parallel relatively reciprocable members of the machine are indicated generally by the numerals Ill and l I, respectively, themember ll normally preceding the member H) as the machine is advanced by an operator who pulls it after him. The operating handle is indicated at I2 and comprises a generally U- shaped tubular member with a portion l2 disposed parallel to the parallel axis of members It! and H and two downwardly and forwardly inclined legs l2 which terminate in horizontal portions I2 Each such horizontal portion I2 is rigidly attached as by clips l3 to the frame of member H, and extends forwardly of member H, bridging the space between members [0 and II, as shown most clearly in Figure 3, a downturned end I2 at the end of each portion l2 havingaffixed thereto a slide 14 which is retained within aguide or trackway comprising parallelV-shaped track or rail members I 5 rigidly mounted upon member Hi. The handle structure just described, therefore, comprises also a tying means which unites members l0 and H for simultaneous movement'forwardly or rearwardly, permitting an operator to manipulate these 'members asone in the ordinary operation of the machine, the connection between the handle structure and one of the members, i. e., member ID, being, however, of such nature that this member can move longitudinally in either direction for limited distance relatively to member H and to the handle. In the normal operation of the machine, however, both members ii! and l I will move longitudinally, the total relative movements of these members being a summation of the movements of both rather than the result of movement of one member only while the other member remains stationary.

- Members Ill and ll are generally similar in construction although the height of member H1 is less than the height of member ll. Each comprises an upper truss-like portion fabricated of suitable horizontally extending structural members, and vertically disposed structural members, tog ether comprising a relatively elongated rigid structure which is rectangular in vertical transverse section as shown. The several members which to gether comprise the truss-like upper portion of member H! are indicated by the letter T and the several members which together comprise the truss-like portion of the member H are indicated by the letter T. Beneath each such truss-like structureis an elongated pan-like ele- V protecting the truss T or T ment 20, these two elements being preferably identical in construction and each comprising a bottom plate 2| and upstanding marginal flanges 22 at the sides and ends, the bottom plate 2| being substantially rectangular in plan. Detachable wear plates 23 underlie bottom plates 2| and comprise the work-engaging members of the machine. The wear plates 23 may be removed and replaced when worn and each is formed with a diagonally extending ridge 24, the work-engaging surface thus being divided into two angularly disposed triangular surfaces, substantially as and for the purpose set forth in the Crock application previously mentioned.

The weight of the truss-like upper portion of each of the relatively reciprocable members, together with the weight of a portion of the motor and motor support, is transmitted to the bottom plate 2| of each member through resilient or vibrating damping means preferably comprising a series of rubber blocks 25 the upper end of each of which abuts against the lower face of a short channel-like bracket member 27 rigidly attached to the truss T (or T) above it and the base of which rests against the web of a short channel-like member 28 the lower ends of the legs of which are welded or otherwise suitably secured to base plate 2|. A bolt 29 passes downwardly through the horizontal web of member 29 and a second bolt 29' passes upwardly through the web of member 28, the ends of these bolts being bonded to the Opposite ends of block 26, respectively. Each base plate 2| is thus resiliently attached to the truss above it, a series of intermediate rubber blocks 26 absorbing the vibrations emanating from bottom plate 2 I, which plate is vibrated at high frequency in the normal operation of the machine, thus above it, as the case maybe, and the superposed motor support and motor. The end of each truss is connected to the end of the associated underlying bottom plate 2| by means which has the capacity to transmit longitudinal and transverse thrust but which also absorbs vibration. Each such means in-- cludes a bracket R secured to the truss end and brackets S and S secured to the adjacent plate, the bracket R being U-shaped in horizontal section and its lower end being loosely tied by bolts to the brackets S and S, as shown in Figures 2 and 6, rubber spacing blocks maintaining the bolt heads in tight engagement with the associated brackets and serving to absorb any horizontally acting vibrations which might otherwise be transmitted from the plate 2| to the truss-like upper portion of each of the members l0 and H.

Each bottom plate 2| has directly mounted on it a unit for effecting its vibration and preferably this unit is of the type shown comprising a plurality of individual vibrators V disposed in axial alignment and equidistantly spaced apart, the rotors of the several vibrators V being operatively connected by short connecting drive shafts S through suitable universal couplings so that all eccentrics on one bottom pan will be revolved at the same angular velocity and will maintain phase relationship with each other. The several vibrators V are relatively simple in construction each including a shaft 30 mounted in suitable bearings 3| supported upon a channel-like base member 32 the legs 32' of which have their lower ends welded or otherwise rigidly attached to base plate '2 I, there being fixed upon each shaft 30, intermediate to its supporting bearings 3|, an eccentric weight 33. Upon one of the connecting shafts S is mounted a pulley 35, which is adapted to be rapidlyrevolved in the normal operation of the machine, thus rotating the eccentric weights 33 in unison and causing vibration of the bottom plate 2|, the frequency of vibration being preferably in the neighborhood of 5000 to 8000 per minute.

The truss member T of member I has rigidly mounted thereon an extension frame E which comprises uprights 38 and longitudinally extending angle members 39, members 39 being parallel and together comprising a guide and support for one end of the engine frame, which frame is generally indicated at F and which extends transversely of and overlies both members i0 and H, as most clearly shown in Figure 3. That end of the engine frame F which overlies member II is equipped with angle members 40 which slidably engage angle members 39 previously referred to, the engine frame F thus being restrained against movement transversely of members l0 and II but being mounted for sliding movement longitudinally of these members, that portion of the frame which overlies member l0 having a downwardly projecting part 42 equipped with spaced anti-friction rollers 43 which rest in a rollway 44 extending longitudinally of truss T of member ID.

The actuating motor is indicated generally at M and is seen to be bolted or otherwise suitably rigidly secured upon the motor frame F. The details of the motor need not be described. It is preferably an internal combustion engine but may be any suitable type of prime mover having the capacity to develop sufficient power to operate the vibration devices previously described and to likewise effect relative longitudinal movements of the members H1 and II. The motor shaft is seen to be equipped with two pulley members, indicated at and 5|, respectively. By means of a belt 52 the smaller pulley 50 is operatively connected to a pulley 53 of relatively large diameter, mounted upon a shaft 54, supported in bearings 55 rigidly mounted upon the truss-like frame T of member ll. Fixed on shaft 54 is a second pulley 56 this last mentioned pulley being connected by means of a belt 51 with the relatively large pulley 58 fixed on shaft 59 carried by bearings 60 rigidly supported upon the frame portion T of member II. Projecting from one face of pulley 58 is an eccentric pin 62 which is connected by means of a long link 63 to a pin 64 which is rigid with the frame T of member ID. Through this driving connection it is quiteapparent that, when the motor M is active, the link 63 will serve to thrust member H1 in one direction and member H in the opposite direction as the pulley 58 revolves, reversing the directions of relative movement of these members twice for each rotation of shaft 59 and pulley 58.

The larger motor driven pulley 5| is connected by means of a belt 56 to a pulley 6'! fixed on a shaft 68 mounted in bearings 69 rigid with a frame 10 which is secured to the frame extension E of member II by bolts being held by these bolts against movement longitudinally of the frame extension, but in such manner that the frame 10 as a whole can be rocked upwardly or downwardly through a relatively minor angle of rotation about a horizontal axis in the plane of this frame and passing transversely through bolts 1|. Mounted on shaft 68 are two pulleys I3 and 14, respectively, pulley 13 being operatively connected by means of a belt with pulley of member I I, previously referred to, and pulley 14 being operatively connected by means of a belt 16 with a pulley 11 on a short countershaft i8 upon which shaft is fixed a second pulley 19 which is connected by a belt 80 with pulley 35 of member l8, also previously described. It is thus clear that when the motor is in operation 7 connected from the vibratory elements and also from the mechanism for reciprocating members in and H, this being effected by sliding the motor frame longitudinally of member I I, thus loosening belts 52 and 65. .The means which normally holds the motor supporting frame F in fixed relation with respect to member II, and which may be utilized to shift the motor and operatively disconnect it from ulley 53 may be most clearly perceived from an inspection of Figures 1, 2 and 8. In these figures the right-hand end of the motor frame is shown to be connected to an operating handle 8] by links 82 one end of each link being pivoted to the motor frame and the downturned end 82' of the link at its'opposite end being pivotally connected to the end of a relatively short operating arm or lever 83 rigidly mounted upon the shaft 84 upon which the operating arm 8! is fixed. If the arm occupies the position in which it is shown in full lines in Figure 1 the motor frame F occupies its extreme right-hand position and the belt 52 is tight. If the operating arm 8! is moved to the position in which it is shown in full lines in Figure 8 the motor frame occupies its extreme left-hand position, the belt 52 being thereby loosened so that the motor may continue to run without effecting rotation of pulley 53.

It has been previously explained that the frame 18 upon which shaft 68 is rotatably supported may be slightly tilted about a horizontal axis extending through the bolts H and to effect this slight tilting motion, and thereby to effect slight vertical movements of shaft 68 and the pulleys 13 and 14 mounted thereon, there is provided an operating element comprising a transversely extending portion 85 normally retained in the position in which it is shown in full lines in Figures 1 and 2, by a' springpressed retainer element 81, and the longitudinally extending or leg portions 85 of which are pivotally connected to the frame extension E, for rocking movement about a horizontal axis transverse to the machine, one point of pivotal connection being indicated at 88 in Figures 1 and 8. Each leg 85 of element 85 is provided with a portion 85 at the end thereof adjacent its point of pivotal attachment to the frame extension E, which projects upwardly and has aflixed thereto a transversely extending pin 90 which enters a slot in the adjacent side frame member of the rocking frame 10. When member 85 is in the position in which it is shown in full lines in Figure l the frame 18 is slightly elevated above the horizontal upper members of frame E, i. e., its left-hand end as seen in Figure l is spaced from the supporting frame but, when it occupies the position in which it is shown in full lines in Figure 8, after having been released by the latching element 81, the frame 18 rests directly upon the frame extension having been rocked downwardly about the horizontal axis through bolts ll, shaft 68 and pulleys i3 and 14 having been lowered and belts l5 and i5 loosened. The driving connections between shaft 68 and the vibratory elements supported upon the pans 2 are, therefore, broken and the engine may continue to operate while these vibratory devices remain inactive. Other forms of clutch means may be employed but those which have been 'disclosed have proven to be particularly suitable in use.

It may be desired, and is frequently desired in actual practice, to disconnect entirely one or the other of the vibratory elements and to rely upon one only to effect the necessary vibration of the concrete over which the machine is passed. The vibratory element associated with member 10 may be disconnected by disconnecting the belt 88. If it is desired to retain this vibratory ele ment and to render the other inoperative the belt 15 may be removed. If it be desired to vibrate the work contacting surface of member H only belt 80 may be eliminated, likewise the vibrator mounted on member 10 and also pulley 14, belt 16, pulley I1 and shaft 18, as shown in Figure 4.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. A machine for smoothing the surface of a slab of freshly deposited concrete including, in combination, two elongated smoothing members the work engaging undersurfaces of which are disposed substantially in a common plane and 7 the axes of which are parallel, a rotatable eccentric device directly mounted on one of said mem- Jeers for vibrating the same, a motor for relatively reciprocating said elongated members and operating said eccentric device, means mounting the motor upon said members for limited movement longitudinally thereof, means for moving said motor longitudinallyof said members, along said first-mentioned means, and locking the same relatively to one of said members, and driving connections between said motor and said eccentric device and between said motor and said members whereby the device may be operated to vibrate the member upon which it is mounted and said members may be relatively reciprocated by power supplied by themotor, said driving con-' nections being effective when said motor is moved to one position upon said motor mounting means and being rendered ineffective when said motor is moved to a second position along said motor mounting means.

2. The combination set forth in claim 1 in which the motor mounting means comprises two parallel ways, one fixed upon each smoothing member and extending longitudinally thereof, the motor is fixed upon a motor supporting base mounted for sliding movement on both of said ways, and means is provided for fixing the motor base in predetermined ways.

GEORGE EARL TROXELL.

position in one of said 

